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Report to Congressional Requesters:
United States Government Accountability Office:
GAO:
November 2009:
Surface Transportation:
Efforts to Address Highway Congestion through Real-Time Traffic
Information Systems Are Expanding but Face Implementation Challenges:
GAO-10-121R:
GAO Highlights:
Highlights of GAO-10-121R, a report to congressional requesters.
Why GAO Did This Study:
Growing congestion on our nation’s roads results in wasted time and
fuel, which adversely affects the economy and the environment. State
and local government agencies and private companies disseminate real-
time traffic information to help travelers decide whether to use
alternative, less congested routes. Legislation enacted in 2005
required the U.S. Department of Transportation (DOT) to establish the
Real-Time System Management Information Program, in order to provide
states the capability to monitor traffic and travel conditions on major
highways and share that information. As requested, this GAO report
addresses, among other things, (1) how the public and private sectors
disseminate real-time traffic information to the public, (2) actions
DOT has taken to establish the Real-Time System Management Information
Program, and (3) experts’ views on the need for a nationwide real-time
traffic information system and its potential characteristics.
To conduct this study, GAO visited sites in California and Florida,
which have well-developed traffic information systems; reviewed and
analyzed DOT reports and data; and interviewed transportation
officials, experts, and other stakeholders. GAO is not making any
recommendations at this time because DOT has not finalized the proposed
rule it issued in January 2009, and there was no consensus from the
experts GAO interviewed as to whether an increased federal role in this
area is appropriate or what this role might be.
What GAO Found:
States and local agencies and the private sector use a variety of
services and technologies to disseminate real-time traffic information
to the public. For example, state and local agencies deploy electronic
traffic signs and services that provide information via a nationwide
511 phone number, and private companies operate Web sites that provide
information for cities across the country. The coverage provided by
these services and technologies is expanding, but there are gaps in
coverage and variations in aspects of real-time traffic information,
such as the quality of the data collected and the extent to which state
and local agencies share their data. The private sector is expanding
coverage, in part by using newer technologies to increase the
collection of traffic data. Like the public sector, the private sector
faces limitations to its coverage and data quality.
To establish the Real-Time System Management Information Program, DOT’s
Federal Highway Administration (FHWA) issued a proposed rule in January
2009 that, when finalized, could improve the coverage, quality, and
sharing of traffic information. The rule proposes requirements for
states to make available certain traffic information, such as travel
time, on major highways and to meet data quality standards, including
standards for timeliness. State and local government officials GAO
interviewed said that these improvements would allow the public to
better select the most efficient route to reach their final
destination, which could reduce congestion and yield other benefits.
Yet state and local officials also told GAO that the proposed rule’s
time frames to develop the program are too short and would be difficult
to implement without additional funds. DOT expects to issue the final
rule in February 2010 and is currently considering options to address
such concerns. According to FHWA, its division offices will monitor
states’ compliance with the final rule.
Experts GAO interviewed generally agreed that a nationwide real-time
traffic information system is needed to help address current gaps in
information coverage and inconsistencies in data quality. Many of these
experts noted that reported mobility and environmental benefits, such
as travel time savings and reduced emissions, could be increased under
a nationwide system. However, experts held varying views on the
potential characteristics of such a system. Some said that the
anticipated results of current efforts related to real-time traffic
information by DOT, states, and the private sector would lead to the
development of a nationwide real-time traffic information system and
considered these efforts sufficient. Others envisioned a nationwide
system that would go beyond current efforts. For example, in their
visions, DOT would take a strong leadership role or partner more with
the private sector to disseminate information. However, experts cited
potential challenges in designing and implementing a nationwide system,
including reaching consensus on the form of the nationwide system and
funding constraints.
DOT reviewed a draft of this report and provided a technical comment
that GAO incorporated.
View [hyperlink, http://www.gao.gov/products/GAO-10-121R] or key
components. For more information, contact David J. Wise at (202) 512-
2834 or wised@gao.gov.
[End of section]
November 30, 2009:
Congressional Requesters:
Growing congestion on our nation's roads is a challenge for many
metropolitan and nonmetropolitan areas. Traffic congestion results in
wasted time and fuel for travelers and commercial truckers, thereby
adversely affecting the economy and the environment. According to
transportation researchers, in 2007, congestion in urban areas resulted
in 4.2 billion hours of time spent waiting in traffic and 2.8 billion
gallons of extra fuel used, at a total cost of $87.2 billion.[Footnote
1] Among the tools that the U.S. Department of Transportation (DOT) has
identified to help reduce congestion are real-time traffic information
systems and technologies,[Footnote 2] which can be used to disseminate
traffic information to the public to help travelers--including
commuters and long-distance travelers--decide whether to use
alternative, less congested routes.
Agencies in state governments and metropolitan areas, as well as
private companies, deploy and operate real-time traffic information
systems and technologies to provide traffic and travel information to
the public. Recognizing the potential for real-time traffic information
to decrease congestion, Congress incorporated requirements related to
real-time traffic information into the 2005 authorization of federal
surface transportation programs. Specifically, the Safe, Accountable,
Flexible, Efficient Transportation Equity Act: A Legacy for Users
(SAFETEA-LU) made DOT responsible for establishing a program--called
the Real-Time System Management Information Program--that would provide
all states the capability to monitor real-time traffic and travel
conditions on major highways and enable them to share that information
with state and local governments and the traveling public.[Footnote 3]
Furthermore, DOT has identified real-time traffic information
initiatives as high-priority efforts to address congestion.
Given the potential benefits of real-time traffic information to the
nation, the House Committee on Transportation and Infrastructure asked
us to provide information on existing real-time traffic information
systems, current and potential future efforts to improve such systems
and create a nationwide system, as well as the impacts and costs of
existing systems. Our objectives for this review were to determine (1)
how state and local agencies and the private sector disseminate real-
time traffic information to the public, and the completeness of current
coverage; (2) what actions DOT has taken to establish the Real-Time
System Management Information Program required by SAFETEA-LU, and
stakeholders' views on these actions; and (3) how selected experts view
the need for and benefits of a nationwide real-time traffic information
system, how they envision such a system, and what the related
challenges may be. The results of our work are contained in enclosure
I. To address the committee's interest in the impacts and costs of
existing systems, we examined what studies have found about the
impacts--particularly on mobility, the environment, and the economy--
and the costs of these systems. These issues are discussed in enclosure
II. This report focuses on real-time traffic information that is
disseminated to the public.[Footnote 4]
To address the first objective, we interviewed--and reviewed relevant
reports and studies obtained from--DOT officials; representatives of
national organizations involved in real-time traffic information
initiatives, such as the Intelligent Transportation Society of America;
state and local transportation officials; and private companies
involved in real-time traffic information initiatives.[Footnote 5] We
also conducted site visits in California and Florida[Footnote 6] and
analyzed 2007 data from DOT surveys on the deployment of Intelligent
Transportation System (ITS) technologies, including real-time traffic
information technologies, to determine the types of real-time traffic
information technologies used in metropolitan areas and the coverage
provided by these technologies.[Footnote 7] To address the second
objective, we reviewed relevant sections of SAFETEA-LU, interviewed DOT
officials on actions the department has taken to address SAFETEA-LU's
requirement that DOT establish the Real-Time System Management
Information Program, and reviewed DOT's proposed rule and guidance
related to this program. To determine stakeholders' views on DOT's
proposed program, we interviewed selected state and local officials and
two private companies that provide real-time traffic data, and also
analyzed comments that stakeholders submitted to DOT on the proposed
program.[Footnote 8] To address the third objective, we interviewed 19
experts from DOT, state and local transportation agencies, academia,
and the private sector. (See enclosure III, table 6.) We identified
these experts with assistance from the National Academy of Sciences,
seeking geographic diversity and expert knowledge of various aspects of
real-time traffic information systems and technologies. Finally, to
obtain information on the impacts and costs of real-time traffic
information systems, we identified and reviewed relevant studies from
selected literature databases. The studies we reviewed quantified the
impacts of real-time traffic information technologies and systems,
discussed the costs, or reported the results of benefit-cost analyses.
We reviewed the methodologies of these studies to ensure that they were
sound and determined that they were sufficiently reliable for our
purposes.
We conducted this performance audit from January 2009 to November 2009,
in accordance with generally accepted government auditing standards.
Those standards require that we plan and perform the audit to obtain
sufficient, appropriate evidence to provide a reasonable basis for our
findings and conclusions based on our audit objectives. We believe that
the evidence obtained provides a reasonable basis for our findings and
conclusions based on our audit objectives. Additional information about
our scope and methodology is provided in enclosure III.
Background:
Real-time traffic information systems, along with other types of ITS,
can be used to improve traffic flow and reduce congestion.[Footnote 9]
Traffic congestion results from many sources, such as recurring high
levels of daily traffic, as well as nonrecurring events like traffic
incidents, special events, and bad weather that can limit the usable
physical capacity of existing roadways. Existing research has shown
that real-time traffic information systems can alleviate traffic
congestion by providing travelers with information on traffic and other
travel conditions, as well as on alternative routes. See enclosure II
for information regarding this research. Real-time traffic information
is one type of traveler information disseminated to the public. Other
types of traveler information include transit, weather, and parking
information.
State and local agencies, as well as private companies, deploy real-
time traffic information systems that collect real-time traffic data
using various technologies, aggregate and translate these data into
useful information, and disseminate that information to the public
using various technologies (see fig. 1).[Footnote 10],[Footnote 11] The
technologies that support real-time traffic information collection and
dissemination are rapidly evolving. Travelers, for example, are
increasingly using newer technologies--such as cell phones that can
access Web sites and receive text messages and in-vehicle navigation
devices--to obtain traffic information during travel.[Footnote 12]
Figure 1: Examples of Technologies Associated with Real-Time Traffic
Information Systems:
[Refer to PDF for image: illustration]
Data collection:
Real-time traffic data are collected using various technologies:
* Aerial surveillance helicopters;
* Video surveillance cameras;
* Fixed sensors[A];
* Vehicle probes[B].
Data aggregation and translation:
Private and public entities aggregate and translate these data into
information.
Information dissemination:
Information is disseminated to the public through various technologies:
* Telephone;
* Television;
* Internet;
* Radio/highway advisory radio[C];
* Dynamic message signs[D];
* Devices used in vehicles (e.g., cell phones, navigation devices).
Source: GAO.
[A] A fixed sensor is a technology that is stationary at the roadside
or embedded in the road to monitor traffic flow.
[B] Vehicle probes use roaming vehicles and portable devices to collect
data on travel times. Vehicle probes include cell phones and Global
Positioning System (GPS) devices.
[C] Highway advisory radio uses radio stations to broadcast traffic-and
travel-related information to travelers using AM radio.
[D] Dynamic message signs are permanent or portable electronic traffic
signs that give travelers information on traffic conditions and travel
times, among other things.
[End of figure]
Real-time traffic information systems disseminate various types of
information to the public such as:
* road closure information, including road or lane closures that result
from construction, maintenance, special events (such as parades),
crashes or other incidents;
* weather conditions affecting roadways and road conditions; and:
* traffic flow information, such as travel times, travel delays, or
vehicle speeds.
Travelers can use real-time traffic information to help make decisions
before they travel (pre-trip) and during travel (en route). The need
for various types of information depends on the traveler. For example,
to reach their destination as efficiently as possible, some commuters
may need pre-trip information, such as travel delays or times, so that
they can adjust their route or time of departure. Commercial drivers
may be more concerned with obtaining en route information, such as
construction or roadway conditions, since their long itinerary does not
allow them to observe real-time traffic conditions for their entire
trip prior to their departure. Interregional travelers may need traffic
information for both their origin and destination, sometimes requiring
them to retrieve information from several real-time traffic information
systems operated by various agencies.
DOT promotes the deployment of real-time traffic information
technologies. For example, DOT's ITS Joint Program Office and the
Federal Highway Administration (FHWA) promote the deployment of these
technologies through activities such as conducting research, providing
technical assistance to state and local agencies, and acting as a
clearinghouse for guidance, best practices, and lessons learned. In
addition, DOT's Research and Innovative Technology Administration
(RITA) ITS Web site includes both deployment statistics and databases
on the benefits and costs of various ITS technologies, including real-
time traffic technologies. Furthermore, DOT, through cooperative
agreements with standards development organizations such as the
Institute of Transportation Engineers, helps to develop ITS standards
that define, among other things, how ITS systems (including real-time
traffic information systems), products, and components can exchange
information. In 2005, SAFETEA-LU gave DOT the responsibility of
establishing the Real-Time System Management Information Program.
SAFETEA-LU also required DOT to establish data exchange formats to
facilitate the sharing of traffic data across jurisdictional boundaries
and the availability of traffic information nationwide. DOT is
currently developing an ITS strategic plan that will identify the
direction, goals, and objectives for the department's ITS program over
the next 5 years. In developing this strategic plan, DOT is working to
further define its role in promoting real-time traffic information
systems.
Agency Comments:
We provided a draft of this report to DOT for its review and comment.
DOT officials provided a technical comment on our report, which we
incorporated.
We are sending copies of this report to interested congressional
committees and the Secretary of Transportation. The report also is
available at no charge on the GAO Web site at [hyperlink,
http://www.gao.gov].
If you or your staff have any questions on this report, please contact
me at (202) 512-2834 or wised@gao.gov. Contact points for our Offices
of Congressional Relations and Public Affairs may be found on the last
page of this report. GAO staff who made contributions to this report
are listed in enclosure IV.
Signed by:
David J. Wise:
Director, Physical Infrastructure Issues:
Enclosures:
List of Requesters:
The Honorable James L. Oberstar:
Chairman:
The Honorable John L. Mica:
Ranking Member:
Committee on Transportation and Infrastructure:
House of Representatives:
The Honorable Peter A. DeFazio:
Chairman:
The Honorable John J. Duncan, Jr.
Ranking Member:
Subcommittee on Highways and Transit:
Committee on Transportation and Infrastructure:
House of Representatives:
The Honorable Mike Rogers:
House of Representatives:
The Honorable Russ Carnahan:
House of Representatives:
[End of section]
Enclosure I:
Public and Private Sectors Use a Variety of Dissemination Technologies
but Gaps in Coverage Exist:
Dissemination and Coverage:
Federal Role:
* The Department of Transportation (DOT) initiated the development of
511 Traveler Information Services by asking the Federal Communications
Commission (FCC) to set aside a three-digit telephone number nationwide
for traveler information services. FCC granted this request in July
2000 and issued a rule on 511 stating that DOT’s role was to
“facilitate ubiquitous deployment” of these services. The rule went
into effect in February 2001.
* In response, DOT helped form the 511 Deployment Coalition—a coalition
of public agencies, industry groups and associations, and private
companies—to encourage the growth of 511 services.
* DOT provided technical expertise and limited start-up funds. DOT
offered money to all states, up to $100,000, for planning the
implementation of 511 services.
* DOT’s current role is to
- provide “targeted assistance” with the goal of having 511 deployed
nationwide, and
- create awareness of the 511 system.
DOT has carried out various activities to promote the deployment of
real-time traffic information technologies by state and local
governments, in addition to its efforts to promote 511 services. For
example,
* DOT distributes information on best practices, Intelligent
Transportation Systems (ITS) standards, and lessons learned related to
the deployment of these and other ITS technologies. DOT also provides
some technical assistance on ITS.
Funding Sources:
DOT does not provide funding to state and local governments
specifically for the deployment of real-time traffic information
technologies and systems.
* The Safe, Accountable, Flexible, Efficient Transportation Equity Act:
A Legacy for Users (SAFETEA-LU) authorizes states to use their annual
federal-aid highway funding for developing and implementing these
technologies and systems. (These funds are derived from the Highway
Trust Fund and are provided to the states mostly through formula grant
programs.)
* States generally finance real-time traffic information systems and
technologies using a combination of federal and state funds. However,
the proportions vary. For example, California officials told us that
they have mainly used state funds while Florida officials told us that
they have mainly used federal funds.
State and Local Agencies Disseminate Traffic Information through 511
Traveler Information Services:
* Most states and some local agencies disseminate traffic information,
as well as other types of traveler information, through 511 Traveler
Information Services (see figure 2).
- These services provide information via the telephone (using an
interactive voice response automated system) and the Internet. By
dialing the three-digit number or accessing the state or local 511 Web
site, travelers can obtain various types of traveler information,
including information on traffic and road conditions as well as
construction- and weather-related traffic problems.
- The types of information provided by these services vary. For
example, some services provide information on travel times and roadway
weather conditions, while others do not. In addition, the way that
information is presented on 511 Web sites varies.
* According to the 511 Deployment Coalition, as of September 2009, 39
services were operating in 36 states. In addition, 511 services were
available to over 181 million Americans (60 percent of the population),
according to DOT.
- Thirty-two were statewide services.
- Seven were metropolitan or regional services. California has four 511
services operating within its borders.
- Some metropolitan or regional 511 services, such as those in
California, are operated by local agencies; while others, such as those
in Missouri and Massachusetts, are operated by the respective state
department of transportation.
* While the volume of calls received by 511 services varies
significantly, overall, these services have received a large number of
calls. According to the 511 Deployment Coalition, as of July 2009,
these services have received over 151 million calls nationwide since
their inception in 2001.[Footnote 13]
* 511 services are expanding. For example, Pennsylvania launched its
service in September 2009, and a five-county system in Southern
California is expecting to launch its service by the end of 2009. Four
additional states—Delaware, Maryland, Mississippi, and South Carolina—
are planning to have operational 511 services in 2010.
* Although 511 services are expanding, some states, such as Texas and
Michigan do not plan to implement such services. States without 511
services may choose not to establish them because they lack adequate
traffic data and funding. Furthermore, rather than using 511 services,
some states may disseminate traffic information using other methods,
such as the Internet and dynamic message signs.
Figure: 511 roadside signs, like the one shown above, are used to
promote awareness of the 511 travel service:
[Refer to PDF for image: photograph]
Source: San Francisco Bay Area’s Metropolitan Transportation
Commission.
[End of figure]
Figure 2: Status of 511 Traveler Information Services, as of September
2009:
[Refer to PDF for image: U.S. map and associated data]
511 is operational:
Alaska:
Arizona:
Colorado:
Florida:
Georgia:
Idaho:
Iowa:
Kansas:
Kentucky:
Louisiana:
Maine:
Minnesota:
Montana:
Nebraska:
Nevada:
New Hampshire:
New Jersey:
New Mexico:
New York:
North Carolina:
North Dakota:
Oregon:
Pennsylvania:
Rhode Island:
South Dakota:
Tennessee:
Utah:
Vermont:
Virginia:
Washington:
Wisconsin:
Wyoming:
511 expected to be operational by 2010:
California:
Delaware:
Maryland:
Mississippi:
South Carolina:
511 not expected to be operational by 2010:
Alabama:
Arkansas:
Connecticut:
District of Columbia:
Hawaii:
Illinois:
Indiana:
Massachusetts:
Michigan:
Missouri:
Ohio:
Oklahoma:
Texas:
West Virginia:
Metropolitan or regional area with 511 service:
Sacramento/Northern California regional area:
San Francisco Bay metropolitan area:
Eastern Sierra regional area:
San Diego regional area:
St. Louis metropolitan area:
Cincinnati/Northern Kentucky regional area:
Eastern Massachusetts regional area:
Sources: 511 Deployment Coalition (data); MapArt (base map).
[End of figure]
State and Local Agencies Use Other Methods for Disseminating Real-time
Traffic Information:
* Based on DOT’s most recent surveys of ITS deployment in large
metropolitan areas (conducted in 2007), state and local agencies in
these areas disseminated real-time traffic information to the public
primarily through the Internet, e-mail, television and radio, dynamic
message signs, and Highway Advisory Radio.[Footnote 14]
* These technologies provided information on traffic incidents, travel
time, and travel speeds on roads in these metropolitan areas.[Footnote
15]
- Most metropolitan areas disseminated information on traffic
incidents, and significantly fewer disseminated information on travel
times and travel speeds. (See table 1.)
- State and local agencies disseminated information on freeways more
frequently than on arterial roads.[Footnote 16] (See table 1.)
Table 1: Percentage of Metropolitan Areas in Which Incident, Travel
Time, and Travel Speed Information Was Disseminated to the Public in
2007:
Type of information: Incident;
Percentage of metropolitan areas: Freeways: 87%;
Percentage of metropolitan areas: Arterial roads: 68%.
Type of information: Travel time;
Percentage of metropolitan areas: Freeways: 36%;
Percentage of metropolitan areas: Arterial roads: 19%.
Type of information: Travel speed;
Percentage of metropolitan areas: Freeways: 32%;
Percentage of metropolitan areas: Arterial roads: 16%.
Source: GAO analysis of DOT data.
Note: These percentages are based on responses from state and local
agencies in large metropolitan areas to DOT surveys on freeway
management and arterial management. Ninety-four metropolitan areas
responded to the freeway management survey in 2007 (about an 89 percent
response rate), and 102 metropolitan areas responded to the arterial
management survey in 2007 (about a 95 percent response rate). See
enclosure III for more information on the surveys.
[End of table]
* Some states are collaborating to disseminate traffic information
across states or across multiple agencies within a jurisdiction. For
example:
- Northwest Passage Corridor Coalition: Wisconsin, Minnesota, North
Dakota, South Dakota, Montana, Wyoming, Idaho, and Washington
coordinate the information they disseminate to the public, particularly
on interstates that cross multiple states.
- Transportation Operations Coordinating Committee (TRANSCOM): State
and local agencies in New York, New Jersey, and Connecticut formed this
coalition, which collects and disseminates real-time incident and
construction information to over 100 member agencies and the public in
the New York metropolitan area.
- I-95 Corridor Coalition: States along the I-95 Corridor, from Maine
to Florida, formed this coalition, which provides information via a Web
site on traffic conditions and travel time.
Dynamic message signs, like the one shown above, are electronic
roadside signs displaying traveler information that can be updated in
real time. These signs can provide travelers with en route information
on incident and closures, travel times, and traffic and weather
conditions. Source: DOT. [See PDF for image: photograph]
The images shown at this traffic management center, located in Orlando,
Florida, were taken from traffic cameras. The traffic cameras collect
real-time traffic data, and the center aggregates the data from the
cameras and from other technologies and then disseminates relevant
traffic information to the public. Source: Florida Department of
Transportation. [See PDF for image: photograph]
Geographic Coverage Provided by State and Local Data Collection
Technologies Is Limited:
* Although state and local agencies disseminate traffic information
through various methods, the information available for dissemination to
the public is limited because the geographic coverage of the
technologies the agencies deploy within their areas of operations to
collect traffic data, such as fixed sensors and cameras, is limited.
* Based on DOT’s 2007 surveys, technologies used by state and local
agencies for collecting real-time traffic data covered about 39 percent
of the combined freeway miles in the 64 large metropolitan areas that
provided this information.[Footnote 17] While the percentage is up from
33 percent reported for 2004, it reveals a significant gap, given that
freeways account for the majority of the nation’s traffic, congestion,
and travel time variability.
- The cost of deploying and maintaining technologies that collect
traffic data, such as fixed sensors, is a major factor limiting the
roadway mileage public agencies can cover.
* Although DOT does not have comparable information on the collection
of traffic data for arterial and rural roads, DOT and state officials
told us that coverage is significantly lower for these roads than for
freeways.
- The main factor limiting the collection of accurate data on arterial
roads is cost because more data collection technologies are needed to
capture traffic data between the many entrances and exits on arterial
roads (e.g., for gas stations, shopping centers, and buildings). Also,
arterial traffic is a greater challenge to measure because signalized
intersections often interrupt traffic flow and make it harder to
predict.
- The coverage in rural areas is lower mainly because the delivery of
power and communications to real-time traffic detection technologies in
isolated areas can be cost prohibitive unless there is a specific
safety demand—such as a high crash rate. Additionally, congestion in
rural areas is much lower than in metropolitan areas, lessening the
need for real-time traffic information.
Measures of Data Quality:
Good data quality is needed to provide useful information to travelers
so that they can make the most efficient travel decisions. The quality
of traffic data is determined by the data’s timeliness, accuracy, and
availability.
* Timeliness—the time from when an event or condition occurs to when it
is reported by real-time information dissemination technology.
* Accuracy—how close the reported data are to “ground truth,” or actual
conditions.
* Availability—how much of the data designed to be collected by the
real-time information collection technology is actually made available.
State and Local Agencies Vary in the Quality of the Traffic Data They
Collect and the Extent to Which They Share Traffic Information:
* The quality of real-time traffic data collected, including the data’s
timeliness, accuracy, and availability, varies by state and local
government.
- The timeliness of dissemination to the public depends on the type of
information disseminated (i.e., incident information, travel time) or
geographic location (i.e., metropolitan or nonmetropolitan area). For
example, it may take longer to disseminate information in rural areas
compared with urban areas because state DOTs may not have the available
resources or infrastructure to collect and report information quickly
in rural areas.
- Although a key data collection technology used by public agencies—
fixed sensors embedded in the roadway—is generally accurate, there is
variation in how reliably these sensors function. In cases where
sensors do not function, traffic data are not available from them. In
California, for example, some districts have sensors that function 50
percent of the time, while other districts’ sensors function 90 percent
of the time. The poor reliability of the sensors in some districts is
generally due to hardware failure, such as broken wiring and missing
parts.
* The extent to which states and local agencies share or exchange data
and information varies.
- According to the 511 Deployment Coalition, there are three basic ways
to transfer and share data or information from 511 systems: calls, data
transfer, and application or database sharing—23 services currently
transfer calls, 0 transfer data, and 9 share applications or databases.
(See table 2.)
- Some states, such as Alaska, Louisiana, Massachusetts, and Missouri,
do not transfer calls, transfer data, or share databases or
applications. The main reason these states do not share data,
particularly through data transfer or database sharing, is that they do
not want to incur the cost of matching data or developing a matching
database for two or more systems.
Table 2: Extent to Which 511 Services Share or Exchange Data and
Information:
How information and data are shared: Call transfer: One 511 system
transfers calls to another 511 system.
Number of states and metropolitan/regional areas: 23;
States and metropolitan/regional areas: Sacramento, Cincinnati/Northern
Kentucky, Colorado, Florida, Georgia, Idaho, Iowa, Kansas, Maine,
Montana, New Jersey, North Dakota, New Hampshire, New Mexico, New York,
North Carolina, South Dakota, Tennessee, Utah, Vermont, Virginia,
Washington, Wisconsin.
How information and data are shared: Data transfer: The underlying data
systems are accessible to other 511 systems, enabling those systems to
exchange information with neighboring jurisdictions without
transferring calls.
Number of states and metropolitan/regional areas: 0;
States and metropolitan/regional areas: No states or local agencies
transfer data.
How information and data are shared: Application or database sharing
Deployers use the same underlying application to run their 511 systems.
Number of states and metropolitan/regional areas: 9;
States and metropolitan/regional areas: Eastern Sierra (California),
Iowa, Kansas, Montana, New Jersey, North Dakota, Rhode Island, South
Dakota, Vermont.
Source: GAO analysis of 511 Deployment Coalition data.
[End of table]
Private Companies Disseminate Traffic Information through Newer
Technologies:
Historically, privately operated news and media outlets have
disseminated traffic information over radio and television broadcasts.
In recent years, private companies have begun to disseminate traffic
information through newer technologies such as cell phones, the
Internet, and navigation devices in vehicles, among others.
* The services provided by the companies that use these newer
technologies include:
- e-mail and cell phone alerts about traffic congestion and incidents;
- Web sites that provide various types of traffic information,
including personalized drive times and live video; and
- navigation devices (in-vehicle and portable) that can provide
information on traffic flow and speed, estimated travel times, and lane
closures, among other things.
Some private companies disseminate traffic information directly to the
public. These companies provide basic traffic information to the public
for free on Web sites and more detailed information for a fee. Some
private companies provide traffic information to state and local
agencies or other private companies, which then disseminate this
information.
Furthermore, some private companies disseminate traffic information
nationally, mainly in metropolitan areas. Following are examples:
* Westwood One disseminates real-time traffic information to the public
nationwide through its affiliations with 2,400 radio stations, more
than 170 television stations, and more than 250 Web sites.
* Clear Channel’s Total Traffic Network disseminates real-time traffic
data in 95 cities via in-car or portable navigation devices, broadcast
media, and wireless and Internet-based services.
* NAVTEQ Traffic is available in more than 120 markets across the
nation. The company disseminates traffic information to the public
about road construction, traffic speeds, and incidents through in-
vehicle and personal navigation devices, cell phones, and Web sites.
NAVTEQ Traffic also provides traffic information to other private
companies that disseminate information through navigation devices.
* A number of other companies, such as Google and Yahoo!, disseminate
real-time traffic information—such as traffic flow and speed—nationally
via Web sites and other means.
New Private Sector Data Collection Technologies Are Helping to Expand
Coverage:
Private companies are expanding the coverage of information that is
disseminated by both public and private entities by using new
technologies to increase the collection of real-time traffic data.
* Some private companies are using newer technologies, such as vehicle
probes, to collect real-time data on travel time and speed (see fig.
3). These companies are collecting data beyond what state and local
governments collect. For example, INRIX—a company that focuses on
collecting and aggregating real-time traffic data—collects data using
commercial fleet vehicle probes and other technologies. An advantage of
such technologies is that data are collected on arterial roads and
other roads where there are no fixed collection technologies (such as
fixed sensors).
Federal Role:
DOT is conducting research and development to improve traffic
information coverage by both the public and private sectors.
* Through its Safe Trip-21 initiative, DOT—in partnership with state
and local agencies, the private sector, and academia—is testing the use
of vehicle probes to generate real-time data and provide travelers with
current information on traffic congestion, roadway conditions, and
alternative travel options. Vehicle probes use roaming vehicles and
portable devices to collect data on travel times and speeds. Vehicle
probes include cell phones and Global Positioning System (GPS) devices.
Test sites are being operated in the San Francisco Bay area and in the
I-95 Corridor along the East Coast.
* DOT has also conducted some evaluations—such as a recent assessment
of the current state of traveler information—to help determine what
activities are needed to make real-time information more accurate and
complete.
Figure 3: Vehicle Probe Technology for Collecting Real-Time Traffic
Data:
[Refer to PDF for image: illustration]
Vehicle 1: Wireless signal detected at 8:04:26 a.m.
Vehicle 2: Wireless signal detected at 8:06:58 a.m.
Travel distance (2 miles), divided by: Travel time (.042 hours),
equals: Speed (47.6 MPH).
Sources: GAO and the I-95 Corridor Coalition.
[End of figure]
Public-private partnerships are expanding data that state departments
of transportation can use in disseminating real-time traffic
information. For example, the Alabama department of transportation
purchased data from INRIX on roughly 125 miles of roads in the
Birmingham area to generate travel times for dynamic message signs, and
the state plans to expand its contract to cover the entire state.
Despite Their Advanced Technologies, Private Companies Face Certain
Limitations in the Coverage and Quality of Data They Collect:
Private companies face certain limitations in the coverage of data they
collect. Some examples are as follows:
* Market disincentives (e.g., little demand for real-time traffic
information) discourage private companies from collecting data on and
disseminating information about rural roads and minor arterials.
* Data collected by vehicle probes in commercial fleets depend on where
these fleets travel. More specifically, some commercial fleets, such as
delivery companies and taxicabs, may travel only on assigned routes or
may not travel on freeways.
* Some state departments of transportation require that private
companies pay for access to public data. However, some private
companies told us that although such data could enhance their coverage,
they often have chosen not to pay for access because the data are not
of high enough quality to merit payment.
The quality of data collected using the newer technologies has the
following limitations:
* Data from vehicle probes, such as GPS devices and cell phones, may
not be collected from enough vehicles to achieve the sample size
required for accuracy.
* Some commercial fleets avoid travel during peak periods. As a result,
probe data collected from these fleets may not accurately reflect
traffic or travel conditions during peak periods.
Furthermore, the public sector may not be able to determine the quality
of real-time traffic information it receives from private companies
because (1) it may have limited access to the underlying data that is
collected and aggregated by these companies and (2) the methods these
companies use to collect and aggregate the data may be proprietary.
[End of Dissemination and Coverage]
DOT's Actions:
SAFETEA-LU Requirements:
In 2005, Section 1201 of SAFETEA-LU required that the Secretary of
Transportation establish a program to provide all states the capability
to:
* monitor, in real-time, the traffic and travel conditions of major
highways, and;
* share that information to facilitate national and regional highway
traveler information, among other things.
SAFETEA-LU did not include a deadline for the Secretary to establish
this program.
SAFETEA-LU does not provide separate funding to implement this program.
However, Section 1201 of SAFETEA-LU authorizes states to use their
annual federal-aid highway funds provided through the Highway Trust
Fund to fund implementation of this program, as well as other ITS
projects.
DOT Has Proposed a Program That Has Potential Benefits, but Some
Stakeholders Are Concerned about Time Frames and Costs:
DOT Has Proposed a Program that Aims to Improve Traffic Information
Coverage, Quality, and Sharing:
To fulfill requirements in SAFETEA-LU, the Federal Highway
Administration (FHWA) issued a Notice of Proposed Rulemaking in January
2009 to establish the Real-Time System Management Information Program.
[Footnote 18] The proposed rule contains minimum requirements for
states to make information on traffic and travel conditions available
through real-time information programs and to share this information.
[Footnote 19]
* FHWA currently plans to issue a final rule in February 2010.[Footnote
20]
The proposed rule aims to create general uniformity among real-time
information programs to ensure consistent service to travelers and
other agencies. It also aims to improve the availability of
information, which could lead to the dissemination of more information
to travelers by public agencies and private companies, as well as to
better traffic control by public agencies, among other things.
* The proposed rule requires states to make certain information
available on all interstates[Footnote 21] within 2 years and on
selected metropolitan-area, noninterstate “routes of significance”
within 4 years.[Footnote 22] (See table 3.)
States that do not currently collect this information will have to
select an approach to achieve compliance from a variety of options,
including installing data collection technologies or contracting with
private companies to obtain the data, thus improving real-time traffic
information coverage. These requirements could also provide a basis for
the development of a new 511 service in states that do not provide this
service because they lack sufficient data.
Table 3: Types of Information Required on Interstate and Selected
Noninterstates, in Metropolitan and Nonmetropolitan Areas:
Type of information required: Roadway or lane closures due to
construction activities;
Interstates (implement within 2 years): Metropolitan areas: [Check];
Interstates (implement within 2 years): Nonmetropolitan areas: [Check];
Selected noninterstates (implement within 4 years): Metropolitan areas:
[Check];
Selected noninterstates (implement within 4 years): Nonmetropolitan
areas: Not required.
Type of information required: Roadway or lane closures due to traffic
incidents;
Interstates (implement within 2 years): Metropolitan areas: [Check];
Interstates (implement within 2 years): Nonmetropolitan areas: [Check];
Selected noninterstates (implement within 4 years): Metropolitan areas:
[Check];
Selected noninterstates (implement within 4 years): Nonmetropolitan
areas: Not required.
Type of information required: Roadway weather conditions;
Interstates (implement within 2 years): Metropolitan areas: [Check];
Interstates (implement within 2 years): Nonmetropolitan areas: [Check];
Selected noninterstates (implement within 4 years): Metropolitan areas:
[Check];
Selected noninterstates (implement within 4 years): Nonmetropolitan
areas: Not required.
Type of information required: Travel time along highway segments;
Interstates (implement within 2 years): Metropolitan areas: [Check];
Interstates (implement within 2 years): Nonmetropolitan areas: Not
required;
Selected noninterstates (implement within 4 years): Metropolitan areas:
[Check];
Selected noninterstates (implement within 4 years): Nonmetropolitan
areas: Not required.
Source: GAO analysis of DOT information.
Note: Metropolitan areas refer to geographic areas with populations
over 1 million, designated as Metropolitan Statistical Areas by the
Office of Management and Budget. The proposed rule noted that, as of
December 31, 2006, 49 metropolitan areas had populations over 1
million.
[End of table]
The proposed rule indicates that all state real-time information
programs that are funded in whole or in part through the Highway Trust
Fund would be subject to its requirements and that states would need to
demonstrate compliance prior to authorization of funds for ITS
projects.
* According to FHWA officials, the agency’s division offices, one of
which is located in each state, will monitor compliance and will work
closely with any states that are facing challenges and allow them
flexibility. FHWA plans to provide states with additional guidance to
help them meet requirements.
The proposed rule also establishes minimum data quality requirements
for the information that states are required to make available.
Specifically, the rule establishes minimum requirements for timeliness,
availability, and accuracy. (See table 4.)
* To the extent that states adhere to these requirements, they should
improve data quality nationwide or at least improve the quality of data
from those entities that do not already meet those minimum
requirements.
Table 4: Timeliness, Availability, and Accuracy Requirements for Real-
Time Traffic Information in Proposed Rule:
Type of information required: Roadway or lane closures due to
construction activities;
Requirements: Timeliness[A] for metropolitan areas: 10 minutes;
Requirements: Timeliness for nonmetropolitan areas: 20 minutes;
Requirements: Availability[B]: 90%;
Requirements: Accuracy[C]: 85%.
Type of information required: Roadway or lane closures due traffic
incidents;
Requirements: Timeliness[A] for metropolitan areas: 10 minutes;
Requirements: Timeliness for nonmetropolitan areas: 20 minutes;
Requirements: Availability[B]: 90%;
Requirements: Accuracy[C]: 85%.
Type of information required: Roadway weather conditions;
Requirements: Timeliness[A] for metropolitan areas: 20 minutes;
Requirements: Timeliness for nonmetropolitan areas: 20 minutes;
Requirements: Availability[B]: 90%;
Requirements: Accuracy[C]: 85%.
Type of information required: Travel time along metropolitan area
highway segments;
Requirements: Timeliness[A] for metropolitan areas: 10 minutes;
Requirements: Timeliness for nonmetropolitan areas: Not required;
Requirements: Availability[B]: 90%;
Requirements: Accuracy[C]: 85%.
Source: DOT.
[A] Timeliness requirements refer to the time it takes to deliver the
information.
[B] Availability requirements refer to the percentage of time that the
information is expected to be available, at a minimum, based on the
design of the real-time information program.
[C] Accuracy requirements refer to the percentage of time that the
information is expected to be accurate, at a minimum, based on the
design of the real-time information program.
[End of table]
The proposed rule allows states flexibility in how they will meet the
requirements.
* There is no requirement for a state or other entity using federal
funds to apply any particular technology in collecting the data
necessary to fulfill the program’s specifications. For example, states
may use their existing fixed sensors to collect data on travel times on
highway segments.
* States may use any business approach to establish a real-time
information program. For example, states can collect data on their own,
contract with the private sector to collect all or some of the data, or
purchase information products from the private sector.
* States can employ any technology for disseminating information.
States could continue to provide information through 511 services or
state Web sites. Additionally, FHWA encourages states to partner with
the private sector to disseminate to the public information that is
made available under the proposed rule.
SAFETEA-LU Requirements:
SAFETEA-LU also required the Secretary of Transportation to establish
data exchange formats within 2 years of the act’s enactment to
facilitate the sharing of data on traffic and travel conditions across
jurisdictional boundaries and the availability of such information
nationwide.
SAFETEA-LU further required states to incorporate the data exchange
formats established by DOT into their traffic and traveler information
systems but did not specify a deadline for states’ use of these
formats.
DOT Has Proposed Guidance on Data Exchange Formats:
To fulfill SAFETEA-LU requirements, in 2007, FHWA issued interim
guidance on the use of standard formats for exchanging data on traffic
and travel conditions. These formats, to the extent that states utilize
them, allow the data collected by a state to be available to any other
state or jurisdiction that wants to retrieve the data in the same
format. FHWA plans to finalize the data exchange format guidance after
the Real-Time System Management Information Program regulations are
finalized in early 2010.
* Once finalized and adopted by states, the guidance would support the
proposed Real-Time System Management Information Program by making it
easier for states and jurisdictions to share the basic real-time
traffic information the program requires. The exchange formats in the
guidance link the proposed program requirements to specific ITS
standards for data exchange.[Footnote 23] To the extent that states use
these formats and incorporate these ITS standards, information will be
easier to exchange across multiple jurisdictions.
According to DOT officials, although states are required under SAFETEA-
LU to incorporate the data exchange formats, DOT does not plan to
require states to use them in the near term because the ITS standards
on which the formats are based are still under development.
* DOT officials said that the department could adopt the ITS standards
referenced in the data exchange format guidance when these standards
are finalized, and DOT could then require states to use them.[Footnote
24] However, DOT has no plans to adopt the standards at this time.
DOT has not obtained information on what data exchange formats states
use since its 2004 surveys of ITS deployments in large metropolitan
areas, but agency officials said that they may obtain this information
in their next ITS deployment survey effort in 2010. Furthermore,
according to DOT officials, the agency’s division offices will monitor
how well states are following the data exchange format guidance.
Stakeholders Have Cited Benefits of the Proposed Program:
State and local officials,[Footnote 25] as well as private sector
representatives, have cited a number of potential benefits of the
program.
* Most state and local government officials and private sector
representatives we interviewed said that improved coverage and
information sharing would provide travelers more information so that
they have the opportunity to choose the most efficient route to reach
their destination, thus providing the opportunity to reduce congestion
and obtain potential benefits to the environment, the economy, and
disaster evacuation efforts.
* Some private companies that submitted comments on the proposed rule
said that the program would advance the data collection market and
would provide them with additional opportunities to fill gaps in public
agencies’ data collection.
State and Local Stakeholders Have Cited Time Frames and Costs as
Challenges in Implementing the Proposed Program:
Most state and local government officials that we interviewed cited
challenges in implementing the program within the specified time frames
and said that the program would be difficult to implement without
additional funds. Because some states and local governments are facing
budget constraints, the implementation of a real-time information
program may not be a priority.
According to some state and local transportation agencies that
submitted comments to the proposed rule, the proposed requirements may
not take into account local needs and could be challenging to implement
even for states with existing 511 services. For example, the
Metropolitan Transportation Commission, which operates San Francisco
Bay Area’s 511 service, said that there is little need for roadway
weather information in areas of the country where weather does not
significantly affect travel. Furthermore, Kansas noted that it would be
challenging for them to collect certain traffic data, such as on
incidents in rural areas, because they may have limited or no resources
or infrastructure in these areas to collect this data and report it to
their statewide 511 service.
DOT is currently considering options to address stakeholders’ concerns
as it finalizes the program’s requirements. We are not making
recommendations to DOT about the Real-Time System Management
Information Program at this time because the agency’s efforts to
establish the program are still in the preliminary stages.
[End of DOT's Actions]
Nationwide System:
Mobility improvements are typically measured in terms of decreases in
delay and travel time, and improvements to the environment are measured
by decreases in emissions and fuel consumption. See enclosure II for
examples of studies that discuss the impact of real-time traffic
information systems and technologies on mobility and the environment.
Most Selected Experts Said a Nationwide System Is Needed, but Their
Visions of Such a System Varied:
Most Experts Saw a Need for a Nationwide System:
Seventeen of the 19 experts we interviewed said that a need exists for
the development of a nationwide real-time traffic information system.
* Some of these 17 experts noted that current approaches to developing
real-time traffic information systems are fragmented because state and
local transportation agencies generally develop and use these systems
within their own jurisdictions, leading to gaps in coverage and
inconsistencies in the quality and types of data collected.
- Many of these experts emphasized that, in their view, information
coverage would be expanded and data quality improved under the
nationwide system they envisioned, resulting in benefits for mobility
and the environment beyond existing real-time traffic information
systems.
- Some experts also said that they believe that further enhancements in
the sharing of information under a nationwide system could provide
potential benefits to the economy and improve coordination of emergency
response efforts that might not be realized under existing state or
regional systems. For example, improved information sharing could allow
commercial truckers to better plan their interstate trips and, in turn,
reduce delivery times or make delivery times more reliable. It also
could allow multijurisdictional areas to communicate better prior to,
during, and after an emergency.
Two of the 19 experts we interviewed, however, said that they saw no
need for the development of a nationwide system.
* One said that there was no need, in part, because adjoining states or
jurisdictions that need to share information have already developed
methods for doing so, such as states that are a part of the I-95
Corridor Coalition. This expert said that multiple regional systems
across the nation would be sufficient.
* The other said the benefits of such a system would not be sufficient
to justify the level of investment that would be needed to develop it.
The 17 experts that said there was a need for a nationwide system had
varying views on the type of nationwide system that is needed (see fig.
4).
* Seven of these 17 experts either envisioned a nationwide system that
would be similar to the anticipated results of current efforts by DOT,
state and local transportation agencies, and the private sector or said
that current efforts are already leading to a nationwide system.
* Ten of these experts envisioned a nationwide system that would go
beyond current efforts, such as a system creating a national user
interface for disseminating information, but these visions varied.
•
Some experts said that current efforts are not sufficient to develop a
nationwide system. For example, one expert noted that DOT’s proposed
rule on the Real-Time System Management Information Program would
actually create statewide systems, rather than a nationwide system.
For the purposes of this review, current efforts that some may see as
leading to a nationwide real-time traffic information system include:
* DOT’s efforts to establish the Real-Time System Management
Information Program;
* state and local transportation agencies’ efforts to expand coverage
of 511 Traveler Information Services; and;
* the private sector’s efforts to collect, aggregate, and disseminate
real-time traffic information across the nation.
Most of these 10 experts envisioned little change in the roles of state
and local transportation agencies—that is, the agencies would continue
to deploy, or partner with other public agencies or private companies
to deploy, real-time traffic information technologies that collect,
aggregate, and disseminate real-time traffic information.
Figure 4: Views of Experts on Whether a Nationwide Real-Time Traffic
Information System Is Needed and Whether Such a System Should Go Beyond
Current Efforts:
[Refer to PDF for image: illustration]
19 experts interviewed:
* 2 saw no need for the development of a nationwide system;
* 17 saw need for the development of a nationwide system:
- 7 envisioned a nationwide system similar to results of current
efforts;
- 10 envisioned a nationwide system that would go beyond current
efforts.
Source: GAO.
[End of figure]
DOT is currently developing an ITS strategic plan that will identify
the direction of the department’s ITS program over the next 5 years.
DOT has sought stakeholders’ views in developing this plan, including
views on what its role in real-time traffic information systems should
be. Some have called for DOT to strengthen its role in this area. For
example, one stakeholder commented that it is critical for DOT to
develop a variety of standards and guidelines for data exchange and for
those standards to be adopted by public and private stakeholders.
Visions of a Nationwide System beyond Current Efforts Varied:
The 10 experts that envisioned the development of a nationwide system
beyond current efforts had varying views on the appropriate level of
involvement for DOT and the private sector, as well as on the form a
nationwide system could take. Among the aspects of a nationwide system
envisioned by these experts are a strong leadership role by DOT,
increased DOT partnerships with the private sector, and a national
interface for disseminating information. These differing aspects are
not necessarily mutually exclusive. For example, DOT could both take a
strong leadership role and partner with the private sector to collect,
aggregate, and disseminate real-time traffic information.
Strong leadership role by DOT—A few experts envisioned that DOT would
play a strong leadership role in a nationwide system, specifically by
developing and enforcing requirements and providing funding for state
and local transportation agencies to develop and maintain real-time
traffic information systems.
* Some experts said that DOT should take a strong role in developing
and enforcing requirements for the types of information to be collected
and disseminated, data quality, and common data exchange formats, as
well as ITS standards. For example, by ensuring compliance with its new
requirements under the Real-Time System Management Information Program,
DOT could help ensure consistency in the types of information collected
and in the quality of the data.[Footnote 26] In addition, one expert
said that DOT’s reluctance to require that states use ITS standards
will dilute the effectiveness of those standards.[Footnote 27]
* Although SAFETEA-LU does not provide separate funding for states to
implement the Real-Time System Management Information Program, several
experts said additional funding is necessary to develop a nationwide
system. One expert envisioned DOT as a grant-giver or funder of real-
time traffic information programs. In this vision, by directly funding
such programs, DOT could better set and enforce requirements that could
improve data coverage, quality, and sharing.
* Other experts said that DOT could act more like the operator of a
nationwide system. For example, DOT could enter into and manage
agreements with the private sector to collect and disseminate a base
level of real-time traffic information nationwide. Or DOT could develop
and operate a national user interface—such as a phone number or
Internet page—that a traveler, regardless of location, could call or
access to obtain, or be directed to, relevant information.
Increased partnerships with the private sector—While some private
companies currently partner with state and local transportation
agencies, several experts envisioned a nationwide system that would
have even more private sector involvement. Some of these experts noted
that the private sector is using more advanced technology and that a
nationwide system should take advantage of this innovation. Examples
are as follows:
* Two experts envisioned a private company contracted by either DOT or
state and local transportation agencies. In the first vision, DOT would
contract with a private company, and the single contract with DOT could
help ensure the collection of consistent data nationwide. In the second
vision, which would replicate the I-95 Corridor Coalition’s business
model on a national level, state and local transportation agencies
within a region would jointly contract with a single private company to
collect and aggregate data and translate the data into real-time
traffic information. The state and local transportation agencies would
disseminate the information to the public and might also collect and
disseminate additional information beyond the data provided to the
region under the private contract.
* Another expert envisioned that DOT would contract with several
private companies to collect and aggregate data on behalf of state and
local transportation agencies. In this vision, the private sector would
perform most operations needed to support the nationwide system, and
DOT would establish data quality standards and other specific
requirements, such as requirements to ensure consistency in the
information collected and disseminated. Information could be
disseminated to the public by either or both entities.
National user interface for disseminating information—While the current
511 phone number could serve as a national user interface, 511 Traveler
Information Services are not available in all states, and the various
state and regional services do not provide consistent information. Two
experts envisioned a nationwide system—possibly operated by the federal
government or the private sector—that would disseminate information
through a public user interface, such as a common phone number or Web
site. This public user interface would provide consistent information
and would be accessible to travelers from anywhere in the nation, at
any time.
* One expert envisioned a national phone system that would receive
calls centrally and disseminate information to travelers to allow state
and local agencies to focus their resources on data collection without
having to support all the technology required for information
dissemination. Another expert envisioned multiple national interfaces
managed by both the public and private sectors. For example, while
state and local transportation agencies could operate a nationwide user
interface that would provide a base level of real-time traffic
information, private companies could operate another national phone
number, Web site, or other service that would provide more personalized
traveler information, but might also require that travelers pay a fee
for that information. A centralized interface could help ensure
consistency in the types of data collected and in data quality.
Experts Held Similar Views on Needed Nationwide Coverage:
Although experts varied in their views on the form a nationwide system
could take, most said that a nationwide system should, at a minimum,
cover controlled access roads, such as interstates, in both urban and
rural areas. These experts also said that the nationwide system should
cover some key arterial roads.
* One expert noted that information for every road all the time would
be ideal but not feasible.
* Some experts said that while a nationwide system should cover at
least interstates and other controlled-access roads and some key
arterial roads, the types of information collected and disseminated
could vary depending on the characteristics of the road—controlled
access versus arterial and low volume versus high volume.
Experts Cited Challenges in Designing and Implementing a Nationwide
System:
Some experts predicted that reaching consensus on the form of a
nationwide system and the roles of the public and private sectors could
be a major challenge.
* Some experts noted that state and local transportation agencies
prefer to maintain control over efforts within their borders. Thus, a
design that dramatically changed the role or shifted the level of
control or responsibility from the state and local levels to the
federal level or to the private sector could meet with resistance from
states and localities.
* Some experts noted that difficulties in quantifying the benefits and
costs of such a system would make it challenging to determine the most
cost-effective design.[Footnote 28] See enclosure II for results of
studies that conducted benefit-cost analyses of real-time traffic
information systems and the challenges in conducting such analyses.
Experts also cited several potential challenges to implementing a
nationwide system that they said would need to be addressed.
* The most common implementation challenge cited by the experts was the
availability of funding. As previously discussed, some state and local
agencies are already anticipating significant challenges in
implementing DOT’s proposed Real-Time System Management Information
Program because of budget constraints. Any additional modifications,
such as in the format for collecting data or disseminating information,
could be a challenge for state or local agencies, given resource
constraints.
Other implementation challenges cited by experts included:
* the need for a clear and sustained vision;
* the need to ensure consideration of local area needs;
* limited staff expertise, such as states’ limited knowledge of
emerging technologies;
* limited understanding of the data quality needed to provide useful
information to travelers and of how to measure this quality; and;
* limited public awareness and use of traffic information.[Footnote 29]
A few experts noted, however, that resistance to change and funding
challenges could be minimized if a nationwide system were built on
existing efforts or systems, such as 511 Traveler Information Services.
In their view, a nationwide system that significantly changed existing
efforts or systems would meet with resistance and require more
resources.
The above viewpoints may provide information that is useful to
policymakers as they consider the future direction of federal efforts
related to real-time traffic information systems. We are not making
recommendations on this topic at this time, however, because there is
no clear consensus among the experts we consulted on whether an
increased federal role in this area is appropriate or what this role
might be.
[End of Nationwide System]
[End of Enclosure I]
Enclosure II: Impact and Costs:
We conducted a literature review to identify studies from 2004 onward
on the impacts (on mobility, the environment, and the economy) and
costs of real-time traffic information systems and technologies.
Specifically, we targeted our literature search to a few literature
databases, including the Transportation Research Information Services
database—a bibliographic database on transportation issues. We also
searched DOT’s ITS Benefits and Costs databases, which are publicly
available. We reviewed the methodologies of studies identified as
relevant to this report and determined that they were sufficiently
reliable. See enclosure III for more details on our objectives, scope,
and methodology.
In its ITS Benefits and Costs databases, DOT compiles and summarizes
studies on the benefits and costs of ITS, including real-time traffic
information systems. In addition to providing summaries of studies,
DOT’s ITS Costs database also provides information on the capital,
operations, and maintenance costs associated with individual ITS
technologies, including those such as video surveillance cameras and
dynamic message signs that can be used to collect or disseminate
traffic information.
Studies Found Positive Impacts of Real-Time Traffic Information Systems
or Technologies and Identified Costs:
Studies Found Improvements to Mobility and the Environment, but Results
Are Not Generalizable:
Studies we reviewed that quantified the impact of real-time traffic
information systems or technologies found that these systems or
technologies improved mobility and the environment.[Footnote 30] Some
of these studies evaluated real-time traffic information technologies
specifically, while others evaluated the technologies as part of an
overall ITS.
* For example, a study of a traveler information system—consisting of
various technologies that collect, aggregate, and disseminate
information on traffic and travel conditions—for a freeway network in
Los Angeles, California, found that deploying this system decreased
travel time by up to 14 percent. See table 5 at the end of this
enclosure for more details on this study, as well as the results of
other studies we reviewed.
The quantitative impacts of these studies are not generalizable or
comparable because these studies are generally specific to a particular
city or road network and evaluate a specific system or technology.
Few of the studies we reviewed found negative impacts associated with
these systems. One study, however, found that traveler information
systems that recommend alternative routes (such as dynamic message
signs) may, in some cases, cause congestion on these alternative
routes. As a result, a traveler may not experience the intended travel
time reduction.
No Studies Quantified Impacts on the Economy:
We did not identify any studies that quantified the impacts of real-
time traffic information systems and technologies on the economy, such
as on the nation’s gross domestic product (GDP).
However, to the extent that real-time traffic information systems and
technologies reduce congestion and improve mobility, there may be
economic benefits.
* According to the Texas Transportation Institute, in 2007, the cost of
congestion to the nation’s urban economy was about $87 billion.
[Footnote 31]
Some private sector representatives we interviewed told us that, based
on their observations, real-time traffic information technologies can
foster economic expansion by speeding the delivery of people, goods,
and services.
Studies Have Found That Costs Vary with a Range of Factors:
The costs to deploy, operate, and maintain real-time traffic
information systems and technologies vary based on a range of factors
including the size, complexity, usage, coverage, and content provided,
among other things.
* For example, a case study published by the 511 Deployment Coalition
in 2006 summarized the costs of six statewide 511 services. Of the 511
services reviewed, Virginia’s had the largest total cost (about $5.2
million) and Kansas had the smallest total cost (about
$990,000).[Footnote 32] See table 5 for examples of other studies that
documented the costs associated with real-time traffic information
systems and technologies.
According to a draft study conducted for DOT, the costs of technologies
and systems that disseminate real-time traffic information, such as 511
systems, can be more easily measured and tracked than the costs of
technologies and systems that collect and aggregate data.
* The costs of technologies used to collect and aggregate data are more
difficult to isolate because the infrastructure supports multiple
operations, including traffic and incident management operations.
Studies That Conducted Benefit-Cost Analyses Found That Benefits
Outweighed Costs:
Of the 20 studies we reviewed, 8 of these studies compared the benefits
with the costs.
The 8 studies that included a benefit-cost analysis found that the
benefits were greater than the costs. See table 5 for examples of
studies that included benefit-cost analyses.
* A majority of these 8 studies evaluated real-time traffic information
technologies as part of a larger system, such as an Intelligent
Transportation System.
* One study—DOT’s analysis of the Real-Time System Management
Information Program—conducted a benefit-cost analysis of a national
real-time information program.[Footnote 33] As noted previously, this
program contains minimum requirements for all states to make
information available on traffic and travel conditions via real-time
information programs.
- This study found that the present value of total cost savings (about
$30.2 billion) due to benefits to mobility, the environment, and safety
would be greater than the present value of the costs (about $1.2
billion) to establish and operate the program. See table 5 for more
details.
[Side bar:
Impacts that are simulated use assumptions about traveler behavior.
However, travelers’ actual responses to information may differ from the
assumed responses used in the estimate. For example, travelers may
choose not to change their travel plans despite receiving information
about heavy congestion. Or, drivers who switch to other modes of
transportation after receiving information on roadway congestion may
later decide to switch back to driving on these roadways. End of side
bar]
Efforts to Determine Impacts and Conduct Benefit-Cost Analyses Pose
Challenges and May Have Limitations:
It is challenging to determine the comprehensive impacts and conduct
benefit-cost analyses of real-time traffic information systems and
technologies. Furthermore, although studies quantify benefits
associated with these systems and technologies, these studies may have
limitations that affect the certainty of the results. Specifically,
challenges and limitations exist with capturing data, isolating
impacts, and simulating impacts.
* Capturing data. It is challenging to capture data about travelers and
their responses to real-time information, particularly since some
travelers may receive information anonymously anywhere, at any time
(e.g., through the radio or through the Internet).
* Isolating impacts. It is challenging to isolate the quantitative
impacts of real-time traveler or traffic information systems because
external factors can influence evaluation outcomes. As we have
previously reported, once transportation investments are completed,
they become part of an entire transportation system and, therefore, the
effects of the individual project become difficult to isolate,
evaluate, and attribute to the individual project.[Footnote 34]
* Simulating impacts. Many of the estimated impacts of real-time
traffic information systems or technologies are simulated. One
limitation of using simulation methodologies to quantify impacts is
that the methodologies depend on simplified assumptions—such as about
traveler behavior—and therefore, the simulated outcomes may differ from
actual outcomes.
DOT Is Considering Research on Impacts and Is Encouraging Benefit-Cost
Analyses:
DOT is considering a variety of research programs and activities for
inclusion in its ITS strategic plan, which it expects to issue in early
2010. As part of the strategic planning process, DOT has sought input
from stakeholders on ITS research needs.
* One stakeholder group, the American Association of State Highway and
Transportation Officials (AASHTO), noted to DOT that there is a need to
identify and document the benefits of real-time information for
mobility and the environment, as well as for safety, particularly since
collecting and analyzing this information can be costly for most
states.
* DOT officials told us that research that addresses mobility impacts,
or impacts on the environment and the economy, of real-time traffic
information systems and technologies is being considered for inclusion
in the strategic plan.
In response to our 2005 recommendation that DOT encourage cost-
effectiveness analyses, as well as benefit-cost analyses of ITS,
including real-time traffic information systems,[Footnote 35] DOT has:
* included benefit-cost analyses of ITS deployments in a database on
ITS benefits that DOT makes available on its Web site, and;
* promoted a software program—in a guide on resources and tools for
state and local planners—that can be used to evaluate the benefits and
costs associated with ITS investments, including real-time traffic
information systems and technologies.
Table 5: Examples of Studies That Quantified Benefits of Real-Time
Traffic Information Programs, Systems, or Technologies; Identified
Costs; or Conducted Benefit-Cost Analyses:
City or road network evaluated/year study published: Road network in
Irvine, California; 2004;
Program, system, or technology evaluated: Traveler information system
Benefits: Mobility; Savings in travel time of around 5 percent during
morning peak hours (5:45 a.m. to 10 a.m.), assuming that 15 to 20
percent of travelers followed instructions of the traveler information
system. Decrease in the average time to clear incidents by 7 minutes,
based on historical data.
Costs: Information not available.
Benefit-cost analysis: Information not available.
City or road network evaluated/year study published: Freeway network in
Los Angeles, California; 2006;
Program, system, or technology evaluated: Traveler information system
Benefits: Mobility; Savings in travel time of up to 14 percent. Travel
time savings were larger during the evening peak hours (4:00 p.m. to
7:00 p.m.). Decrease in travel time variability of up to 50 percent,
depending on the type of information.
Costs: Information not available.
Benefit-cost analysis: Information not available.
City or road network evaluated/year study published: A construction
work zone on an Interstate in Devore, California; 2006;
Program, system, or technology evaluated: Sensor to collect travel time
data, software to estimate travel time, dynamic message signs, and a
Web site;
Benefits: Mobility; Decreased traffic volumes during weekday peak-hour
traffic in the work zone, causing a reduction in traffic delay from an
expected 90 minutes to an actual 50 minutes. Traffic volumes on
neighboring freeways increased but the increase in travel time on these
roads was insubstantial.
Costs: The total cost of leasing and maintaining the technologies and
of analyzing the data was about $0.2 million.
Benefit-cost analysis: See table note below.
City or road network evaluated/year study published: Arizona, North
Carolina, Utah, Virginia, Kansas, and Washington; 2006;
Program, system, or technology evaluated: Statewide 511 services
Benefits: Information not available.
Costs: On average, the statewide 511 services cost $2.5 million to
design, implement, and operate and maintain for 1 year. Virginia had
the largest total cost (about $5.2 million), and Kansas had the
smallest total cost (about $990,000).
Benefit-cost analysis: Information not available.
City or road network evaluated/year study published: U.S. highway in a
rural area north of Spokane, Washington; 2004;
Program, system, or technology evaluated: Environmental sensor stations
that collect and transmit road weather data, video surveillance
cameras, and Highway Advisory Radio;
Benefits: Information not available.
Costs: The total cost to construct and install these technologies was
$446,807.
Benefit-cost analysis: Information not available.
City or road network evaluated/year study published: Tucson, Arizona;
2005; (a forecast for the year 2025)[A];
Program, system, or technology evaluated: ITS—consisting of 35
technologies including Highway Advisory Radio, dynamic message signs, a
telephone- and Web-based traveler information system, and kiosks.
Benefits: Mobility; Expected decrease in delay due to recurring
congestion by about 6 percent, expected decrease in incident-related
delay by more than 70 percent on freeways, and expected decrease in
annual travel time by 7 hours per resident.
Environment; Expected reduction in annual fuel use by 11 percent and
expected reduction in annual carbon monoxide, hydrocarbon, and nitrous
oxide emissions between 10 and 16 percent.
Costs: The expected average annual cost for implementing, operating,
and maintaining all 35 ITS technologies was about $72 million. More
specifically, the expected annual cost for implementing, operating, and
maintaining the regional telephone- and Web-based traveler information
system and 5 kiosks was $2.1 million.
Benefit-cost analysis: The expected average annual benefit of the ITS
to mobility, the environment, safety, and other areas ($455 million)
was greater than the expected average annual cost to implement,
operate, and maintain the ITS. The benefits outweighed the costs by a
ratio of 6.3 to 1.
City or road network evaluated/year study published: Nationwide; 2009
Program, system, or technology evaluated: Real-Time System Management
Information Program;
Benefits: Mobility; Savings in incident delays of about 321 million
hours, annually.
Environment; Reduced annual hydrocarbon and nitrous oxide emissions by
about 8,200 tons and 11,600 tons, respectively. Reduced annual gasoline
use by about 447 million gallons.
Costs: The present value of the total cost for establishing real-time
information programs in all states and the nation’s 50 largest
metropolitan areas and operating these programs through 2018 would be
about $1.2 billion.
Benefit-cost analysis: The present value of total cost savings (about
$30.2 billion) due to benefits to mobility, the environment, and safety
would be greater than the present value of the costs to establish and
operate the program. Specifically, the present value of the benefits
would exceed the present value of the costs by about $29 billion
through 2018.
Source: GAO analysis of select studies.
Note: Dollar figures are in current dollars, not adjusted for
inflation. The study in Devore, California, found that the net benefit
of implementing the technologies during 18 days of closures due to
construction was estimated to be about $3.6 million. However, we could
not confirm the reliability of this estimate.
[A] This study forecasted the impact of ITS technologies on mobility,
the environment, and other areas in 2025 based on traffic forecasts and
planned ITS deployments for that year.
[End of table]
[End of Enclosure II]
Enclosure III: Objectives, Scope, and Methodology:
Objectives:
The objectives of this report were to determine (1) how state and local
agencies and the private sector disseminate real-time traffic
information to the public, and the completeness of current coverage;
(2) what actions DOT has taken to establish the Real-Time System
Management Information Program required by the Safe, Accountable,
Flexible, Efficient Transportation Equity Act: A Legacy for Users
(SAFETEA-LU), and stakeholders’ views on these actions; and (3) how
selected experts view the need for and benefits of a nationwide real-
time traffic information system, how they envision such a system, and
what the related challenges may be. We also examined what studies have
found about the impacts of real-time traffic information systems and
technologies—particularly on mobility, the environment, and the economy—
and their costs.
Scope:
This report focuses on real-time traffic information that is
disseminated to the public. Real-time traffic information that is used
for traffic management purposes is not in the scope of this report.
Methodology:
To determine how state and local agencies and the private sector
disseminate real-time traffic information to the public and the
completeness of current coverage, we interviewed—and reviewed relevant
reports and studies obtained from—DOT officials; representatives from
national organizations involved in real-time traffic information
initiatives, such as the American Association of State Highway and
Transportation Officials (AASHTO) and the Intelligent Transportation
Society of America (ITS America); state and local transportation
officials; and four private companies involved in real-time traffic
information initiatives. More specifically, we interviewed state and
local officials during site visits in California and Florida. We
selected these locations for site visits because they have well-
developed real-time traffic information systems, have deployed a range
of technologies to collect and disseminate real-time traffic
information, have 511 Traveler Information Services, and have differing
public-private partnership models for collecting, aggregating, and
disseminating real-time traffic information. Furthermore, officials
from DOT, and representatives from AASHTO and ITS America, suggested
that we visit these locations. The four private companies that we
interviewed collect, aggregate, and disseminate real-time traffic
information. To identify these companies, we obtained recommendations
from DOT, AASHTO, and ITS America as to which companies play key roles
in those areas.
We also reviewed and analyzed survey data from DOT’s ITS Deployment
Tracking Database for 2007, the most recent survey year. This database
contains state and local agencies’ responses to multiple surveys on the
deployment of various ITS technologies, including real-time traffic
information technologies, in the nation’s 108 largest metropolitan
areas. The metropolitan areas selected are those that have populations
of more than 50,000. We focused our review on agency responses to two
surveys--one on the deployment of ITS technologies on freeways and the
other on ITS deployments on arterial roads. Nearly all metropolitan
areas responded to both the surveys. We used the survey data in the
database to determine the types of technologies and systems in use and
their coverage. Based on interviews with DOT officials and our analysis
of the data, we determined that the data were sufficiently reliable for
the purposes of this report, which was to provide (1) general
information on the types of technologies and systems used to collect
and disseminate real-time traffic information to the public and (2)
general estimates of the coverage of these technologies, including the
number of metropolitan areas in which incident, travel time, and travel
speed information were disseminated to the public in 2007.
To determine what actions DOT has taken to establish the Real-Time
System Management Information Program, we reviewed and analyzed Section
1201 of the 2005 transportation authorization—SAFETEA-LU—which made DOT
responsible for establishing the program. We also interviewed DOT
officials on their actions to establish the program, and reviewed and
analyzed the proposed rule and related guidance that DOT published in
the Federal Register. To determine stakeholders’ views on the expected
benefits and challenges to implementing the proposed program, we
interviewed selected state and local transportation officials and
representatives of AASHTO and two private companies that provide real-
time traffic data. The state and local officials we interviewed on this
issue were those that we met with during our site visits and those
selected by the National Academy of Sciences (NAS). Later in this
section we provide further details on how NAS selected state and local
government officials and other stakeholders. The private companies we
interviewed were those identified as key data providers by our own work
and NAS. To further identify expected benefits of, and challenges to
implementing the program, we reviewed and analyzed comments that state
and local agencies, private companies, and organizations submitted to
DOT in response to the proposed rule and related guidance that DOT
published in the Federal Register.
To determine experts’ views on a nationwide system, we conducted
semistructured interviews with—and reviewed relevant documentation from—
19 experts about options for implementing a nationwide real-time
traffic information system, including the need for, potential benefits
of, and challenges to implementing such a system.[Footnote 36] The
individuals we interviewed from state and local transportation
agencies, academia, and the private sector (consultants and data
providers) were selected by NAS. NAS selected these experts based on
geographic diversity and their knowledge of various aspects of real-
time traffic information systems and technologies, including the roles
of the federal, state, and local governments and the private sector;
key technologies used in collecting, aggregating, and disseminating
traffic information to the public; various models for providing traffic
information services; and current efforts to implement a nationwide
real-time traffic information system. We identified three officials
from DOT as experts because these individuals work on issues, policies,
and regulations related to real-time traveler or traffic information
and were identified by DOT as points of contact in these areas. The 19
experts we interviewed and their affiliations are listed in table 6.
Table 6: Names of Experts We Interviewed and Their Affiliations:
DOT:
Jane Lappin, Volpe National Transportation Systems Center;
James Pol, ITS Joint Program Office;
Robert Rupert, Federal Highway Administration.
State level associations:
George Schoener, I-95 Corridor Coalition;
James Wright, American Association of State Highway and Transportation
Officials (AASHTO).
State Departments of Transportation:
Anthony Bradford, Georgia Department of Transportation;
David Huft, South Dakota Department of Transportation;
Greg Krueger, Michigan Department of Transportation;
David Lively, California Department of Transportation.
Local transportation agencies:
Matt Edelman, Transportation Operations Coordinating Committee
(TRANSCOM);
David Fink, Houston TransStar;
Carol Kuester, Metropolitan Transportation Commission.
Academia:
Mark Hallenbeck, Washington State Transportation Center;
Christopher Poe, Texas Transportation Institute;
Philip J. Tarnoff, University of Maryland.
Private industry (consultants):
Dean Deeter, Athey Creek Consultants;
Les Jacobson, Telvent Farradyne Inc.
Private industry (data providers):
John Collins, Transportation Business Law and Strategy (formerly with
NAVTEQ Traffic);
Rick Shuman, INRIX.
Source: GAO.
[End of table]
Other Aspects of Our Work:
To describe what studies have found about the impacts (on mobility, the
environment, and the economy) and costs of real-time traffic
information technologies and systems, we conducted a literature review
to identify pertinent studies. Specifically, we targeted our literature
search to the Transportation Research Information Services database—a
bibliographic database on transportation issues—and DOT’s ITS Benefits
and Costs databases. Our search of these databases did not yield
studies on the impacts of real-time traffic information systems and
technologies on the economy. Therefore, we extended our literature
search to additional databases, including the EconLit bibliographic
database—a database in the field of economics—and the ProQuest and
WorldCat databases. Our literature search covered studies published
from 2004 onward.
Through the literature search, we identified a number of studies that
discussed technologies and systems that disseminate, or support the
dissemination of, real-time traffic information to the public. We
further limited our review to studies that evaluated real-time traffic
information technologies and systems in the United States and that (1)
quantified the impacts of real-time traffic information technologies
and systems on mobility, the environment, or the economy; (2)
identified the costs of these systems or technologies; or (3) conducted
benefit-cost analyses. Based on these criteria, we identified a total
of 20 studies that were relevant and applicable to our report. We
reviewed the methodologies of these studies to ensure that they were
sound and determined that they were sufficiently reliable for
describing the impacts and costs of real-time traffic information
systems and technologies.[Footnote 37]
We conducted this performance audit from January 2009 to November 2009,
in accordance with generally accepted government auditing standards.
Those standards require that we plan and perform the audit to obtain
sufficient, appropriate evidence to provide a reasonable basis for our
findings and conclusions based on our audit objectives. We believe the
evidence obtained provides a reasonable basis for our findings and
conclusions based on our audit objectives.
[End of Enclosure III]
Enclosure IV: GAO Contact and Staff Acknowledgments:
GAO Contact:
David J. Wise, (202) 512–2834, or wised@gao.gov.
Staff Acknowledgments:
In addition to the contact named above, Judy Guilliams-Tapia, Assistant
Director; Lauren Akers; Dwayne Curry; Roshni Davé; Bess Eisenstadt;
Kathleen Gilhooly; Brandon Haller; Terence Lam; Kirsten Lauber; Ashley
McCall; Josh Ormond; Madhav Panwar; and Gretchen Snoey made key
contributions to this report.
[End of Enclosure IV]
Footnotes:
[1] David Schrank and Tim Lomax, 2009 Urban Mobility Report (College
Station, Texas: Texas Transportation Institute, 2009).
[2] "Real-time" is a relative measure. Information delivery times
generally range between 10 and 20 minutes.
[3] In 2005, SAFETEA-LU authorized funding for federal surface
transportation programs for highways, highway safety, and transit. See
Pub. L. No. 109-59, 119 Stat. 1144. Section 1201 of SAFETEA-LU
established the Real-Time System Management Information Program but did
not provide separate funding to implement this program. Section 1201 of
SAFETEA-LU authorizes states to use their federal-aid highway funding
for efforts related to this program.
[4] Real-time traffic information can also be used for a range of
traffic management purposes. For example, traffic managers can use this
information to control traffic through signal timing, detect traffic
incidents, and monitor congestion trends. However, traffic management
is not in the scope of this review.
[5] We selected the four private companies to interview because they
were identified by DOT, the American Association of State Highway and
Transportation Officials, and the Intelligent Transportation Society of
America as key companies involved in real-time traffic information
collection, aggregation, and dissemination.
[6] We interviewed state and local officials in California and Florida
because, among other reasons, they have well-developed real-time
traffic information systems and have deployed a range of technologies
to collect and disseminate real-time traffic information.
[7] ITS consists of a range of communications, electronics, and
computer technologies--including those that collect, aggregate and
translate, and disseminate real-time traffic information--that are
designed to improve traffic flow and safety. DOT's ITS deployment
surveys sought responses from state and local agencies to questions on
the deployment of various ITS technologies, including real-time traffic
information technologies, in 108 large metropolitan areas. The
metropolitan areas selected are those that have populations of more
than 50,000. The most recent surveys were conducted in 2007. We
reviewed the reliability of the survey data and determined that the
data were sufficiently reliable for the purposes of this report. See
enclosure III for more details on our methodology.
[8] The state and local officials we interviewed included those we met
with during our site visits and those the National Academy of Sciences
identified as experts in the areas covered by our third objective. The
private companies we interviewed were those identified as key data
providers by the academy, as well as through our own work.
[9] ITS technologies can also be used for improving safety and for
transit management. In 2005, we issued a report on the extent to which
ITS is used as a tool to reduce congestion. See GAO, Highway
Congestion: Intelligent Transportation Systems' Promise for Managing
Congestion Falls Short, and DOT Could Better Facilitate Their Strategic
Use, [hyperlink, http://www.gao.gov/products/GAO-05-943] (Washington,
D.C.: Sept. 14, 2005).
[10] Some local agencies have agreements with their respective state
departments of transportation to collect, aggregate, and disseminate
real-time traffic information to the public. Some state and local
agencies also contract with private companies to conduct such
activities.
[11] Public agencies also use real-time traffic information for traffic
management.
[12] The potential for drivers using cell phones and in-vehicle
technologies to become distracted has become a major safety concern.
Some states have banned or restricted the use of cell phones while
driving. In 2008, GAO addressed safety concerns associated with cell
phones and in-vehicle technologies in its report, Highway Safety:
Foresight Issues Challenge DOT's Efforts to Assess and Respond to New
Technology-Based Trends, [hyperlink,
http://www.gao.gov/products/GAO-09-56] (Washington, D.C.: Oct. 3,
2008). However, the impacts of these technologies on safety are not
within the scope of this review.
[13] Similar nationwide usage information is not available for 511 Web
sites because this usage is not tracked consistently by DOT, states, or
metropolitan areas.
[14] These surveys reflect ITS deployments by state and local agencies,
not deployments by private companies. DOT plans to conduct the next
survey of ITS deployments in 2010.
[15] These technologies may have provided additional types of
information, but DOT’s surveys asked only about incidents, travel
times, and travel speeds.
[16] According to DOT officials, the term "freeways," which is used in
its ITS deployment surveys, refers to controlled access roads that have
no intersections. Arterial roads generally consist of roads that have
signalized intersections.
[17] While 94 metropolitan areas responded to the 2007 survey on
freeway management, 30 of these metropolitan areas did not report
information on technologies for collecting real-time traffic data on
their freeways.
[18] See 74 Fed. Reg. 1993 (Jan. 14, 2009).
[19] According to DOT’s benefit-cost analysis of the Real-Time System
Management Information Program, the present value of the total cost for
establishing real-time information programs in all states and the
nation’s 50 largest metropolitan areas and operating these programs
through 2018 would be about $1.2 billion. See enclosure II for more
details on this analysis.
[20] Before the rule is finalized, it will have to be reviewed by the
Office of the Secretary at DOT and by the Office of Management and
Budget.
[21] Interstate highways are routes designated as part of the Dwight D.
Eisenhower National System of Interstate and Defense Highways.
[22] The proposed rule notes that states should select routes of
significance based on various factors, including their importance for
congestion relief, disaster evacuation, economic growth, and safety.
[23] ITS standards define how ITS systems, products, and components can
be interconnected and exchange information, among other things. Many
ITS standards are consensus-based, meaning that all interested parties
agreed, through cooperation and compromise, on the published standard.
[24] 23 C.F.R. § 940.11(f) requires that all ITS projects funded
through the Highway Trust Fund use applicable DOT-adopted ITS
standards. For DOT to adopt ITS standards, it must first issue a rule,
but it has not yet done so for any of these standards.
[25] Some local agencies have agreements with their respective state
departments of transportation to collect, aggregate, and disseminate
real-time traffic information to the public. Under such agreements,
some local governments may support the state departments in
implementing the requirements of the Real-Time System Management
Information Program.
[26] The proposed rule states that FHWA will monitor compliance and may
decline to approve federal-aid projects, pursuant to 23 C.F.R. § 1.36,
if a state does not comply with the regulations.
[27] DOT, through cooperative agreements with six standards development
organizations such as the Institute of Transportation Engineers, helps
to develop nonproprietary, industry-based, consensus ITS standards. As
noted previously, DOT may adopt ITS standards and require states to
follow them by issuing a rule, but DOT has not yet done so.
[28] If DOT were to issue a rule on a nationwide real-time traffic
information system, a regulatory benefit-cost analysis could be
required to comply with Executive Order 12866 and the Unfunded Mandates
Reform Act of 1995. Executive Order 12866 directs agencies to conduct
economic analyses of significant regulatory actions and to select the
policy that maximizes net benefits to society unless a statute requires
otherwise. The Unfunded Mandates Reform Act of 1995 requires agencies
to choose the least costly, most cost-effective, or least burdensome
option, unless inconsistent with law or the agency head explains why
this option was not adopted.
[29] Some of these challenges currently exist for real-time traffic
information systems and could continue to be challenges for a
nationwide system.
[30] Mobility improvements are typically measured in terms of decreased
delay and travel time, and environmental improvements are measured by
decreased emissions and fuel use.
[31] Schrank and Lomax.
[32] The costs of the two services varied because Virginia’s 511
service covered many roads within the state, and because the state
collected data and ensured data quality 7 days a week. By contrast,
Kansas’ 511 service shared infrastructure with several other states,
which may have contributed to its lower cost.
[33] DOT prepared a benefit-cost analysis of the Real-Time System
Management Information Program to satisfy Executive Order No. 12866 and
the Unfunded Mandates Reform Act of 1995.
[34] GAO, Highways and Transit Investment: Options for Improving
Information on Projects’ Benefits and Costs and Increasing
Accountability for Results, [hyperlink,
http://www.gao.gov/products/GAO-05-172] (Washington, D.C.: Jan. 24,
2005).
[35] [hyperlink, http://www.gao.gov/products/GAO-05-943].
[36] We did not evaluate the experts' options for a nationwide system,
including factors such as the feasibility and implementation costs
associated with these options.
[37] Dollar figures used to describe the costs or cost savings of real-
time traffic information systems and technologies are in current
dollars, not adjusted for inflation.
[End of section]
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